Crumar Mojo and Static Discharge

[DontShoot]

Greetings, all. I"m a first-time poster and long-time reader, and wondering if some folks could assist with the following query.

 

I recently purchased a Crumar Mojo Suitcase, a dual-manual organ. I bought it new from Sweetwater a little over a month ago. I"ve been LOVING the sound and feel of the organ, but I've had the following issue.

 

My particular unit seems to be very sensitive to electrostatic discharge (ESD), and tends to lock up at the slightest little shock. I live in the northeast United States, and we have very dry winters, so the odd static shock when touching a light switch isn"t uncommon. However, if I happen to have built up any static electricity and touch the Mojo"s case while playing it, it will sometimes lock up completely. No more sound (or, alternatively, you get hanging notes). You have no choice but to reboot the organ.

 

I wrote to Crumar"s support division, and they were very helpful, as I"d expected they would be on the basis of the excellent reputation that Crumar has for service.

 

They asked me if I was using an expression pedal, and I was: the Yamaha FC-7. It turns out that this pedal doesn"t play so nice with the Mojo. So I removed it from the equation, but the problem persists.

 

All I have to do is rub my shoes on the carpeted floor of my studio and touch the Mojo"s case, and zap! The organ freezes. The reason it does so, the support department explained, is because it goes into 'protection mode' to prevent damage to the internal components. In other words, this doesn't seem to be a faulty unit: any other Mojo Suitcase, if played in my rig, would behave in the same way according to the support department.

 

They suggested a few possible workarounds (e.g. attaching a MIDI or USB cable to help discharge the static, using a different power source, using balanced audio cables) but so far I"ve still been able to reproduce the problem. I even tried removing my shoes, and while this mostly got rid of the issue, I would sometimes generate static just from shifting on my seat, and that would trigger the same behavior.

 

So here are my questions:

 

1. Does anyone else have a Crumar organ with this issue? If so, have you found any effective solutions that eliminate it completely? (I"m aware of 1 or 2 other posts on this forum that describe the same issue, but it looks like the poster wasn"t able to find a solution, even after buying a new Mojo.) I'm trying to determine whether this is a problem specific to my unit or is more common.

 

2. Secondly, is it unusual for a keyboard to be so susceptible to static discharge? I recognize that my carpeted studio isn't helping matters, but I own several other boards (i.e., Nord Electro 6D, Roland RD-2000, Korg Kross 2, etc.), plus a guitar modeler, a mixer, and lots more gear, and I can"t remember ever receiving a static shock from any of them. Certainly never something that interfered with the functioning of the instrument.

 

I"m aware that some of the Crumar guys occasionally read this forum, and if they do, let me reiterate that I greatly appreciate your support, just as I appreciate the beautiful instrument you have created. I"m reaching out to the forum not to complain about your product but rather to see if anyone has suggestions for how to get around the problem. I really love playing the Mojo and would hate to have to return it. But if it's going to brick on me several times in a gig, I guess I have no choice, right?

 

Any suggestions? Grateful for the forum's help.

[Dave Bryce]

The dual MOJO I had a few years back had the same issue.

 

dB

[DontShoot]

The dual MOJO I had a few years back had the same issue.

 

dB

 

Did you find a workaround for it?

[Dave Bryce]

IIRC, it was not resolved.

 

Only happened twice, so I was just careful around it. Never gigged with itâ¦

 

Welcome to the forum (posting-wise), BTW!

 

dB

[jpgxk3]

HI, try discharging yourself by touching anything metal before you touch your Mojo; corner of a wall that has metal corner bead under the sheetrock, yes I have done that, try your organ stand, seat frame, light switch cover or the screws if the cover is plastic. Been in your position before, I have gotten into the habit of just grabbing my stand framing every time before I use mine. Hope you find a solution, good luck.

[DontShoot]

HI, try discharging yourself by touching anything metal before you touch your Mojo; corner of a wall that has metal corner bead under the sheetrock, yes I have done that, try your organ stand, seat frame, light switch cover or the screws if the cover is plastic. Been in your position before, I have gotten into the habit of just grabbing my stand framing every time before I use mine. Hope you find a solution, good luck.

 

Many thanks. So I guess it's not a dealbreaker for you?

[Old No7]

I have a Mojo 61 and other boards and haven't had that issue with them...

 

I seem to recall that low humidity exacerbates the problem (given where you live and the season -- I'm in Maine) and I wonder if running a humidifier * in there for a few days would help lessen the shock.

 

Any moisture you put in the air this time of year will stay there for sure (in the air), so I don't believe there's any downside to trying this.

 

Old No7

 

( * If you have an older house with radiators, a pan of clean water on top achieves the same result. )

[DontShoot]

I seem to recall that low humidity exacerbates the problem (given where you live and the season -- I'm in Maine) and I wonder if running a humidifier * in there for a few days would help lessen the shock.

 

Any moisture you put in the air this time of year will stay there for sure (in the air), so I don't believe there's any downside to trying this.

 

Old No7

 

( * If you have an older house with radiators, a pan of clean water on top achieves the same result. )

 

This is a good idea, but it doesn't address the problem of gigging. Lots of clubs/restaurants/etc. have carpeting and are just as staticky as my studio in the winter. What I'm most concerned about is bricking the organ in the middle of a gig because I shifted in my seat and then brushed the case with my hand. (This has already happened once in a rehearsal).

[Mr -G-]

Once one gets charged, I suspect that touching the stand or anything metal won't make any difference unless the metal is properly grounded (typically connected to the ground of the mains or the pipes of the water supply/central heating (if they are metal, of course!).

[ImproKeys]

Hi DontShoot,

I have been trough this with my new Mojo Classic Dual Manual. You are telling my story, including the support experience. I had issues in two rehearsal spaces, both had a carpet. But I was not able to reproduce it like you are telling, it was at random and not nearly that often. I sent the Organ to repair, they told me there was nothing to fix, but they changed some cables in the audio path. Since then I had one occasion with âhickups'/ crackling and one where the organ froze on start.

 

Last week I played my first organ-only gig on a big stage. My trusty Nord Stage stood at near reach, just in case. Knock on wood - no issues for the whole evening (approx. 4hours). I used a Furman power conditioner, knowing that this would not help in case of static discharge.

 

I really love the sound and layout of the Mojo, so I kept it (still one year warranty left). I have to say I am not happy about support telling me the instrument is securing itself with a shutdown. I own(ed) many many keyboards which never left me feeling like that. My wife told me to not care that much; the Mojo was the cheapest available option and unfortunately I am a not that requested organist. In the rare case of that changing, I might upgrade. ;-)

 

Nonetheless I am very interested in your story and how it will continue.

 

Kind regards from Germany!

[Delaware Dave]

A couple of thoughts:

 

1) it doesn't happen with the Mojo 61, you could return your instrument and purchase a Mojo 61 and optional lower manual, giving you the dual manual option (although one set of drawbars).

2) purchase a DMC122; here is a guy selling one with a Gemini module built in. You get the Mojo organ plus 3 dozen other instruments to boot. the price is dirt cheap... (link)

3) Could you cover the mojo with a wallpaper-like material so that when you touch it you won't get the static charge?

[ABECK]

What about something like an ESD heel strap? I realize that's an odd item to have to wear, but they are cheap enough that you could test it without blowing a lot of cash.

[bill bosco]

I seem to recall that low humidity exacerbates the problem (given where you live and the season -- I'm in Maine) and I wonder if running a humidifier * in there for a few days would help lessen the shock.

 

Any moisture you put in the air this time of year will stay there for sure (in the air), so I don't believe there's any downside to trying this.

 

Old No7

 

( * If you have an older house with radiators, a pan of clean water on top achieves the same result. )

 

This is a good idea, but it doesn't address the problem of gigging. Lots of clubs/restaurants/etc. have carpeting and are just as staticky as my studio in the winter. What I'm most concerned about is bricking the organ in the middle of a gig because I shifted in my seat and then brushed the case with my hand. (This has already happened once in a rehearsal).

had an early mojo . at home it would occasionally lock up . on stage at my church it was unusable , couldn't get any feedback from crumar , couldn't sell it off in good faith , so it stay homed , eventually getting mothballed entirely .a year and a half ago i dug it out of the closet , gutted it , saved the keybeds and the lower shell and converted it to an HX3 powered organ . this one is a keeper

[wineandkeyz]

What about something like an ESD heel strap? I realize that's an odd item to have to wear, but they are cheap enough that you could test it without blowing a lot of cash.

 

I was going to suggest that, but I think you would also need a grounded ESD floor mat, which might be awkward for gigging.

[DontShoot]

@Delaware Dave

 

Thanks for the suggestions. If I'm going to replace it, I'd want another dual manual board with more than one set of drawbars. The Nord C2D has been discontinued and so my options seem to be either an SKX or a Legend. I haven't looked closely at the DMC-122. Maybe I should.

 

As for covering the Mojo with material, I've thought about it, but that would involve making some pretty dramatic changes to the organ that would make it difficult for me to return/sell down the road, I think.

[DontShoot]

Yeah, the heel strap / antistatic mat idea is something I've considered.

 

I guess the larger question is why this is an issue with this particular board. The Crumar support team told me that the Mojo Classic is "a Class II musical instrument (without earth connection)". Is that also true of other keyboards? I have no idea. If it's true of my Nord/Roland/etc. then why aren't they also susceptible to static? If those boards are grounded, then why the decision to use class II wiring on the Crumar? Sorry if these are idiotic questions, but I'm curious.

[Delaware Dave]

Yeah, the heel strap / antistatic mat idea is something I've considered.

 

I guess the larger question is why this is an issue with this particular board. The Crumar support team told me that the Mojo Classic is "a Class II musical instrument (without earth connection)". Is that also true of other keyboards? I have no idea. If it's true of my Nord/Roland/etc. then why aren't they also susceptible to static? If those boards are grounded, then why the decision to use class II wiring on the Crumar? Sorry if these are idiotic questions, but I'm curious.

Great questions for the manufacturer; my experience has been that you won't get answers from them for these questions, that's not how they roll.....

[ABECK]

@Delaware Dave

 

Thanks for the suggestions. If I'm going to replace it, I'd want another dual manual board with more than one set of drawbars. The Nord C2D has been discontinued and so my options seem to be either an SKX or a Legend. I haven't looked closely at the DMC-122.

 

FWIW, I've never had anything remotely like that happen with my DMC Gemini combo. There have been some funky wifi issues reported with the Gemini, but the latest firmware seems to have addressed issues accessing with current browsers.

[jyrkik]

Hi,

 

I do also own a Mojo Classic and do like it a lot. It has worked mostly ok altought I recall getting it to hang up once or twice during the year or two of ownership. In those rare occasions I don`t recall having any specific hints of esd/static charging happening. The thing just hung up without any obvious reason. Luckily(!) due to obvious reasons there has been very little gigs happening lately and these few glitches happening at home studio haven`t bothered me at all.

 

I also happen to have two degrees in electronics and radio engineering and currently work in the R&D of a company designing and manufacturing sensitive measurement equipment. My humble opinion is that any signs of issues like hung ups due to static (dis)charging are signs of some HW design fault(s). Protecting the electronics against static discharge (ESD) issues is a fundamental requirement when carrying out professional electronics design tasks. It`s not black magic, but not exactly trivial either.

 

I have owned also the original dual manual Mojo and Mojo 61. Both served me well without any proplems like this.

 

I also want to repeat that I like the Classic and wouldn`t hesitate to gig with it were it`s otherwise possible. But my rare gigs are very low profile - in other kind of situation I might consider at least to have some back up.

 

Jyrki

[Kurt W]

« the support department explained, is because it goes into 'protection mode' to prevent damage to the internal components»

 

That explanation is strange. If it is a controlled shut down causing hanging notes how do it prevent the internal components? This is rather a question about hardware design an must be solved by the developer. At least you should be offered a return or upgrade.

[DontShoot]

Hi,

I also happen to have two degrees in electronics and radio engineering and currently work in the R&D of a company designing and manufacturing sensitive measurement equipment. My humble opinion is that any signs of issues like hung ups due to static (dis)charging are signs of some HW design fault(s). Protecting the electronics against static discharge (ESD) issues is a fundamental requirement when carrying out professional electronics design tasks. It`s not black magic, but not exactly trivial either.

 

This is helpful. Forgive my ignorance, but what does "HW" mean? Hand-wiring?

[Dave Bryce]

HW = hardware.

 

dB

[Kurt W]

HW means hardware that is electronic components on printed circuit boards, internal power supply, wiring between boards etc. My view is like jyrkik; protecting against static discharge should be an essential part of designing any consumer electronics.

[timwat]

+1

 

My first reaction to seeing this post was that something is poorly designed - for a hardware keyboard to be this susceptible to static electricity suggests to me it would be unreliable for regular gig life until this issue is rectified.

 

An example (for illustrative purposes) would be my Kronos - that thing takes over 90 seconds to boot up. Which is a lifetime if someone trips on a power cord during a song, or the power otherwise goes out for a second like some of the venues I play. So for years I gig with an UPS just in case - you never plan for the power to momentarily glitch. No one is going to plan for a minor static discharge because you happen to be walking on wool carpet. And it seems unreasonable to force the player to wear an ankle strap or similar like you're assembling semiconductor circuit boards.

 

I also realize Crumar is a respected and well-loved manufacturer, and I don't at all want to slag them. I've never even owned any of their products. I hope they'll weigh in here on the forum, as I think they do every once in a while?

[Threadslayer]

 

... until this issue is rectified.

 

Now you're talking!

[sunspot]

Sorry to hear you are having that problem, that is a shame. I agree with others on this - suspect power/grounding design. I had the same issue with a little Dreadbox Typhon synth, and I returned it and got my money back. I've never had any other music device encounter an ESD event that caused it to lock up and reboot in 20+ years and I wasn't willing to start now. Wish I could offer up a good solution, but to me - having to haul around an anti-static mat or wear something on your heel for an inherently flawed design is ridiculous. YMMV.

[drawback]

HI, try discharging yourself by touching anything metal before you touch your Mojo; corner of a wall that has metal corner bead under the sheetrock, yes I have done that, try your organ stand, seat frame, light switch cover or the screws if the cover is plastic. Been in your position before, I have gotten into the habit of just grabbing my stand framing every time before I use mine. Hope you find a solution, good luck.

 

Many thanks. So I guess it's not a dealbreaker for you?

 

Seems to me that if other keyboards aren't going into "protection mode" in dry winter conditions, Crumar has a problem. If I'm not stepping out of line here, you could try contacting Ken Hall (kenheeter) through this forum and see if he has any ideas. Otherwise, I think this would be a dealbreaker for me and I'd press for a refund. Gigging with no confidence in the stability of your instrument is the biggest drag there is.

[DontShoot]

Thanks to everyone for their feedback. Sweetwater has offered to send me a replacement organ, so we'll see if that solves the issue. I can't imagine that *every* Mojo Suitcase owner is dealing with this problem on a daily basis, so maybe it's just a faulty unit. I'll keep my fingers crossed (and hopefully static-free...)

 

Will update the forum either way. Thx again!

[Moonglow]

Thanks to everyone for their feedback. Sweetwater has offered to send me a replacement organ, so we'll see if that solves the issue. I can't imagine that *every* Mojo Suitcase owner is dealing with this problem on a daily basis, so maybe it's just a faulty unit. I'll keep my fingers crossed (and hopefully static-free...)

 

Will update the forum either way. Thx again!

Did you ask them to send you one free of charge?

[Skinny]

Thanks to everyone for their feedback. Sweetwater has offered to send me a replacement organ, so we'll see if that solves the issue. I can't imagine that *every* Mojo Suitcase owner is dealing with this problem on a daily basis, so maybe it's just a faulty unit. I'll keep my fingers crossed (and hopefully static-free...)

 

Will update the forum either way. Thx again!

Did you ask them to send you one free of charge?